AGV motion control method

Abstract

The invention belongs to the technical field of automatic transfer, and particularly relates to an AGV (automatic guided vehicle) motion control method, which comprises the following steps of: dividing a motion track of an AGV into n + 1 sections of paths according to the number n of turning points; the single-section path is divided into an acceleration section, a constant speed section and a deceleration section which are sequentially arranged in the driving direction of the AGV; in the single section of the path, in the driving process of the AGV from the acceleration starting point of the acceleration section to the acceleration ending point, the AGV accelerates from zero to the cruising speed required by the uniform section according to a preset acceleration curve and drives in the uniform section according to the cruising speed, and in the driving process of the AGV from the deceleration starting point of the deceleration section to the deceleration ending point, the AGV decelerates from the cruising speed to zero according to a preset deceleration curve. According to the invention, fine regulation and control of AGV movement can be realized, inertial impacts caused by start-stop and turning stages are significantly inhibited, the transfer efficiency is ensured, the adaptability of the AGV to different loads and ground conditions is improved, and high stability and high safety in the transfer process are ensured.

Description

Technical Field

[0001] This invention belongs to the field of automated transfer technology, specifically relating to an AGV motion control method. Background Technology

[0002] With the continuous development and intelligent upgrading of the manufacturing industry, AGVs, as a transfer tool with good application adaptability and high reliability, have been widely used in various production scenarios and have become an important tool for realizing the integration of production and handling on production lines and building intelligent factories.

[0003] For goods such as retired power batteries, energy storage batteries, and precision electronic components, the high load-bearing capacity and operational stability of AGVs are required due to the precision of the goods and their large overall weight, including the shelving. However, in existing technologies, AGVs generally operate with uniformly set speed parameters, and the movement trajectory of an AGV is not a simple straight line but includes turning points. AGVs with heavy loads are prone to displacement or shaking of goods and shelving at turning points and at the end of the path, affecting the safety of goods transportation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an AGV motion control method that enables precise control of AGV motion, significantly suppresses inertial impact caused by start-stop and turning phases, ensures transfer efficiency, improves the adaptability of AGV to different loads and ground conditions, and ensures high stability and high safety in the transfer process.

[0005] The present invention includes the following steps: S1. Based on the number of turning points n in the AGV's movement trajectory from the transfer start point to the transfer end point, divide the AGV's movement trajectory into n+1 path segments; S2. Divide a single path segment into an acceleration segment, a constant speed segment, and a deceleration segment sequentially arranged along the AGV's travel direction. Within the single path segment, during the AGV's journey from the acceleration start point to the acceleration end point of the acceleration segment, the AGV accelerates from zero to the cruising speed required for the constant speed segment according to a preset acceleration curve, and then travels at the cruising speed in the constant speed segment. During the AGV's journey from the deceleration start point to the deceleration end point of the deceleration segment, the AGV decelerates from the cruising speed to zero according to a preset deceleration curve. The lengths of the acceleration and deceleration segments in the n+1 path segments are fixed, or the lengths of the acceleration and deceleration segments in the n+1 path segments are set according to the AGV's real-time load and the ground friction coefficient.

[0006] Furthermore, in S1, position sensors are installed on the ground or in space where the transfer start point, turning point, and transfer end point are located.

[0007] Furthermore, after the AGV triggers the positioning sensor corresponding to the transfer start point or transfer end point, the AGV is inserted and positioned with the shelf positioning column at the transfer start point or transfer end point, and performs the corresponding loading or unloading operation of the shelf.

[0008] Furthermore, the position sensor is at least one of an RFID tag, a pressure sensor, and an infrared beam sensor.

[0009] Furthermore, in S2, the real-time load of the AGV is divided into three load levels: light load, medium load, and heavy load, according to the load range of the AGV, and the cruising speed decreases as the load level increases.

[0010] Furthermore, when the lengths of the acceleration and deceleration segments in the n+1 segment path are fixed, an acceleration termination sensor is installed on the ground or in the space where the acceleration endpoint of the acceleration segment is located, and a deceleration start sensor is installed on the ground or in the space where the deceleration start point of the deceleration segment is located.

[0011] Furthermore, when the acceleration and deceleration segments in the n+1 path are set based on the AGV's real-time load and the ground friction coefficient: The length of the acceleration or deceleration segment, L1, is 0.1. +0.015·V²+0.5; Where M is the real-time load of the AGV; μ is the ground friction coefficient; and V is the cruising speed.

[0012] Furthermore, the acceleration and deceleration curves are one of the following: S-shaped curves, trapezoidal curves, and sine curves.

[0013] Furthermore, the shelf is equipped with an elastic clamping mechanism for lateral support and cushioning of goods during the AGV's travel along the acceleration and deceleration phases.

[0014] Furthermore, S2 also includes path tracking of the AGV's movement via a navigation system.

[0015] The beneficial effects of this invention are that it divides the motion trajectory of a single transfer stroke of the AGV into n+1 segments based on the number of turning points (n). Each segment employs a three-stage speed control method consisting of an acceleration segment, a constant speed segment, and a deceleration segment, achieving precise control of the AGV's motion. The positioning accuracy of each node along the path can be improved to within 5mm. This method allows for dynamic or fixed setting of the lengths of the acceleration and deceleration segments based on the actual load and ground friction conditions, significantly suppressing inertial impacts caused by start-stop and turning phases, and effectively preventing slippage and swaying of goods and shelves. While ensuring transfer efficiency and improving the AGV's adaptability to different loads and ground conditions, it also ensures high stability and safety during the transfer process, making it better suited for the industrial transfer of heavy and precision goods such as retired power batteries, energy storage batteries, and precision electronic components. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the AGV movement path distribution of the present invention. Detailed Implementation

[0017] This invention provides an AGV motion control method, which includes the following steps: S1. Based on the number of turning points n in the AGV's movement trajectory from the transfer start point to the transfer end point, divide the AGV's movement trajectory into n+1 path segments; S2. Divide a single path segment into an acceleration segment, a constant speed segment, and a deceleration segment sequentially arranged along the AGV's travel direction. Within the single path segment, during the AGV's journey from the acceleration start point to the acceleration end point of the acceleration segment, the AGV accelerates from zero to the cruising speed required for the constant speed segment according to a preset acceleration curve, and then travels at the cruising speed in the constant speed segment. During the AGV's journey from the deceleration start point to the deceleration end point of the deceleration segment, the AGV decelerates from the cruising speed to zero according to a preset deceleration curve. The lengths of the acceleration and deceleration segments in the n+1 path segments are fixed, or the lengths of the acceleration and deceleration segments in the n+1 path segments are set according to the AGV's real-time load and the ground friction coefficient.

[0018] by Figure 1Taking an example, target points I to V are the working points of the AGV. The line connecting any two target points forms a motion trajectory, and the turning points of this line are the turning points. The two target points correspond to the transfer start point and the transfer end point. For example, in the motion trajectory of the AGV with target point I as the transfer start point and target point III as the transfer end point, there are two turning points in the motion trajectory from the transfer start point to the transfer end point, namely points Z1 and Z2, which are divided into three path segments: Q1~Z1, Z1~Z2, and Z2~Z3. Taking the path Q1~Z1 as an example, Q1~J1 is the acceleration segment, J1~J2 is the constant speed segment, and J2~Z1 is the deceleration segment. Q1 is the acceleration start point, J1 is the acceleration end point and the constant speed start point, J2 is the constant speed end point and the deceleration start point, and Z1 is the deceleration end point. The other path segments and the motion trajectories between other two target points are similar.

[0019] Based on the AGV motion control method provided by this invention, the motion trajectory of a single transfer stroke of the AGV is divided into n+1 segments according to the number of turning points (n). Each segment employs a three-stage speed control method consisting of an acceleration segment, a constant speed segment, and a deceleration segment, achieving precise control of the AGV's motion. The positioning accuracy of each node along the path can be improved to within 5mm. This method can dynamically or statically set the lengths of the acceleration and deceleration segments according to the actual load and ground friction conditions, significantly suppressing inertial impacts caused by start-stop and turning phases, and effectively preventing slippage and swaying of goods and shelves. While ensuring transfer efficiency and improving the AGV's adaptability to different loads and ground conditions, it also ensures high stability and safety during the transfer process, making it better suited for the industrial transfer of heavy and precision goods such as retired power batteries, energy storage batteries, and precision electronic components.

[0020] In step S1, position sensors are installed on the ground or in space at the starting point, turning point, and ending point of the transfer. This setup allows for feedback on the AGV's position, improving the accuracy of AGV control as it travels along the path.

[0021] After the AGV triggers the positioning sensor corresponding to the transfer start or end point, it inserts and positions itself with the shelf positioning column at the transfer start or end point, and then performs the corresponding loading or unloading operation on the shelf. This ensures the positioning accuracy of the AGV during loading and unloading, further improving the safety and precision of the transfer operation.

[0022] The positioning sensor is at least one of RFID tags, pressure sensors, and infrared beam sensors. It can be used with only one of them or with a combination of two or more. The specific settings can be selectively configured according to different path environments and spatial conditions.

[0023] In step S2, the real-time load of the AGV is divided into three load levels: light load, medium load, and heavy load, based on its load capacity. The cruising speed decreases as the load level increases. For example, light load (real-time load ≤ 100kg): cruising speed is 1m / s; medium load (100kg < real-time load ≤ 300kg): cruising speed is 0.7 m / s; heavy load (M > 300kg): cruising speed is 0.4m / s. Based on this setting, the cruising speed is adjusted according to the real-time load level, ensuring both efficient operation under light load and stability and safety under heavy load, thus achieving a balance between operational efficiency and safety.

[0024] In the embodiment of this invention where the lengths of the acceleration and deceleration segments in an n+1-segment path are fixed, the lengths of the acceleration and deceleration segments are preset according to the actual site conditions. An acceleration termination sensor is installed on the ground or in the space where the acceleration endpoint of the acceleration segment is located, and a deceleration start sensor is installed on the ground or in the space where the deceleration start point of the deceleration segment is located. Specifically, the acceleration termination sensor and the deceleration start sensor are position sensors. When the acceleration termination sensor is triggered, the AGV stops accelerating and maintains its current speed for uniform travel. When the deceleration start sensor is triggered, the AGV begins to decelerate, maintaining a deceleration curve according to a preset pattern. This achieves precise control of the speed switching points even with fixed lengths for the acceleration and deceleration segments.

[0025] In the embodiment of this invention where the acceleration and deceleration segments in the n+1 segment path are set according to the real-time load of the AGV and the ground friction coefficient, the length of the acceleration or deceleration segment L1 = 0.1 + 0.015 V² + 0.5; where M is the real-time load of the AGV; μ is the ground friction coefficient; and V is the cruising speed. This allows for dynamic adjustment of the AGV's operating parameters, improving its adaptability to complex working conditions.

[0026] The acceleration and deceleration curves are one of the following: S-curve, trapezoidal, or sine curve. S-curves and sine curves are preferred, as they provide smoother velocity changes and further reduce instability caused by abrupt acceleration changes.

[0027] The shelf is equipped with an elastic clamping mechanism, which provides lateral support and buffering for the goods during the AGV's travel along the acceleration and deceleration sections, thereby preventing the goods from tipping over or shifting laterally and further improving the stability of the transfer process.

[0028] S2 also includes path tracking of the AGV's movement through a navigation system, further improving the accuracy and reliability of the AGV's movement, and is especially suitable for path planning and correction in complex or dynamic environments.

[0029] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0030] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.

Claims

1. An AGV motion control method, characterized by, The method comprises the following steps: S1, according to the number n of turning points in the motion trajectory of the AGV from the transfer starting point to the transfer ending point, the motion trajectory of the AGV is divided into n+1 paths; S2, the single-path is divided into an acceleration section, a uniform speed section and a deceleration section arranged in sequence along the driving direction of the AGV; in the single-path, in the driving process of the AGV from the acceleration starting point to the acceleration ending point of the acceleration section, the AGV accelerates from zero to the cruising speed required in the uniform speed section according to the preset acceleration curve, and drives at the cruising speed in the uniform speed section; in the driving process of the AGV from the deceleration starting point to the deceleration ending point of the deceleration section, the AGV decelerates from the cruising speed to zero according to the preset deceleration curve; wherein, the length of the acceleration section and the deceleration section in the n+1 paths is fixedly set, or the length of the acceleration section and the deceleration section in the n+1 paths is set according to the real-time load of the AGV and the ground friction coefficient.

2. The AGV motion control method according to claim 1, wherein In the S1, a position sensor is arranged on the ground or space where the transfer starting point, the turning point and the transfer ending point are located.

3. The AGV motion control method according to claim 2, wherein After the AGV triggers the position sensor corresponding to the transfer starting point or the transfer ending point, the AGV is positioned with the rack positioning column of the transfer starting point or the transfer ending point, and the loading or unloading operation of the rack is performed correspondingly.

4. The AGV motion control method according to claim 2 or 3, characterized by, The position sensor is at least one of an RFID tag, a pressure sensor and an infrared reflection sensor.

5. The AGV motion control method according to any one of claims 1 to 3, wherein In the S2, according to the load range of the AGV, the real-time load of the AGV is divided into three load levels of light load, medium load and heavy load, and the cruising speed decreases with the increase of the load level.

6. The AGV motion control method of claim 5, wherein, When the length of the acceleration section and the deceleration section in the n+1 paths is fixedly set, an acceleration termination sensor is arranged on the ground or space where the acceleration ending point of the acceleration section is located, and a deceleration starting sensor is arranged on the ground or space where the deceleration starting point of the deceleration section is located.

7. The AGV motion control method of claim 5, wherein, When the length of the acceleration section and the deceleration section in the n+1 paths is set according to the real-time load of the AGV and the ground friction coefficient: The length of the acceleration section or deceleration section L1=0.1· + 0.015 · V2+ 0.5; Wherein, M is the real-time load of the AGV; μ is the ground friction coefficient; V is the cruising speed.

8. The AGV motion control method according to any one of claims 1 to 3, 6, and 7, wherein The acceleration curve and the deceleration are one of S-shaped curve, trapezoidal curve and sinusoidal curve.

9. The AGV motion control method according to any one of claims 1 to 3, 6, and 7, wherein The rack is provided with an elastic compression mechanism for laterally supporting and buffering the goods during the driving of the AGV along the acceleration section and the deceleration section.

10. The AGV motion control method according to any one of claims 1 to 3, 6, and 7, wherein In the S2, the driving of the AGV is path tracked by a navigation system.

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